Skid steer vehicles such as skid steer loaders are a mainstay of construction work. In their most common configuration, they have two drive wheels on each side of a chassis that are driven in rotation by one or more hydraulic motors coupled to the wheels on one side and another one or more hydraulic motors coupled to the wheels on the other side.
The wheels on one side of the vehicle can be driven independently of the wheels on the other side of the vehicle This permits the wheels on opposing sides of the vehicle to be rotated at different speeds and in opposite directions. By rotating in opposite directions, the skid steer can rotate in place about a vertical axis that extends through the vehicle itself.
The vehicles have an overall size of about 10 by 12 feet, which, when combined with their ability to rotate in place, gives them considerable mobility at a worksite. It is this mobility that makes them a favorite.
Skid steer vehicles commonly have at least one loader (or lift) arm that is pivotally coupled to the chassis of the vehicle to raise and lower at the operator's command. This arm typically has a bucket, blade or other implement attached to the end of the arm that is lifted and lowered thereby. Most commonly, a bucket is attached, and the skid steer vehicle is used to carry supplies or particulate matter such as gravel, sand, or dirt around the worksite.
As a counterbalance to the loads provided at the front of the vehicle, skid steer vehicles typically have an engine that is located behind the operator. The radiator is also commonly disposed behind the operator, usually at the center rear of the vehicle behind the engine.
Cooling air for the engine is typically drawn into the rear engine compartment through an aperture protected by a grille or grating. This air aperture is most commonly disposed at the very rear of the vehicle. In the skid steer vehicle illustrated herein, for example, the air aperture is a rectangular opening that is located in a rear engine access door.
Skid steer vehicles are operated in dusty and dirty environments. The vehicles are typically used at construction sites for both roads and buildings. These environments are unpaved, and a significant amount of dirt gets stirred up by the passage of vehicles such as skid steers. Further, the method of steering—by skidding—breaks up compacted soil and turns it into loose particles easily lifted by wind and rotating wheels.
These environments cause significant dirt to accumulate around the radiator and other coolers. In skid steers this is a particular problem. They are close to the ground, they steer by skidding, and their cooling air intakes are located at the rear of the vehicle precisely where the wheels and the air disturbed during their passage throws us dirt and dust.
This accumulated dirt reduces the efficiency of the radiator and other coolers. Once sucked into the cooling air aperture, the dust coats the cooling fins of the engine cooling water radiator, oil coolers and other heat exchangers. Common skid steer vehicles have at least two heat exchangers that are cooled by this dirty air: an engine water cooler (or “radiator”) and a hydraulic fluid cooler. As the air passes first through one, and then through the other, dirt, dust and other contaminants carried by the air begin to coat the cooling fins of each of the heat exchangers and plug the air flow passages between adjacent cooling fins. This coating blocks the transfer of heat from the cooling fins of the heat exchangers to the air and must be removed to restore the full operational capacity of the heat exchangers.
To restore efficiency it is necessary to clean the radiator and coolers out regularly. Cleaning the cooling fins requires a strong blast of air and/or water directed through the core of the heart exchangers. This blast of fluid must be of sufficient force to dislodge the dust dirt and other contaminants (small bits of paper, leaves, sticks twigs, etc.) that have lodged between or coat the cooling fins.
It is difficult to access the skid steer radiator and coolers and clean them. A single heat exchanger can be cleaned by directing a blast of air or water through both sides of the heat exchanger core. As long as the operator has access to both sides (both faces) of the heat exchanger it can be cleaned well.
When two heat exchangers are stacked and fastened one in front of the other, however, like two stacked slices of bread, the operator cannot reach both surfaces of the heat exchanger, only one surface (the outer surface) of each. A blast of fluid through two stacked heat exchangers is not satisfactory since the first heat exchanger core slows down, redirects and scatters the blast as it passes through, leaving little force to dislodge dirt, dust and contaminants from the second heat exchanger core.
The radiator and coolers cannot readily be separated to permit better cleaning. In the typical arrangement, the radiator and cooler are fixed to one another with metal straps and are together bolted to a fan shroud. The fan shroud is typically a large funnel-like structure, molded from a fiber reinforced plastic and fixed between the spinning engine fan that draws air through the heat exchangers and the heat exchangers themselves. Even small deflections or misalignments of such a fan shroud can cause it to be chewed up by the spinning fan blades, damaging both the fan and the shroud itself. Further, any disconnection or movement of the heat exchangers and the fan shroud with respect to each other run the risk of producing air leaks. Whenever air is permitted to leak out of or into the cooling air flow path without passing through the heat exchangers and the fan, the cooling air flow is reduced and the efficiency of the heat exchangers drops accordingly. For these reasons, the heat exchangers and the fan shroud are most commonly bolted firmly together and are fixed in place, with no easy provision for moving either heat exchanger.
What is needed, therefore, is an improved skid steer vehicle having a cooling system that is configured to provide better cleaning access. What is also needed is a system that provides access to the space between two stacked radiators. What is also needed is a system for providing access that is easily and quickly operated, without requiring considerably time for disassembly and reassembly. What is also needed is an improved system for sealing the heat exchangers in the radiator one to the other to reduce or eliminate air leaks. It is an object of this invention to provide these advantages. While not every claimed aspect of the invention provides all these advantages, each of these advantages is provided by at least one claimed aspect.